Oct 7 (Reuters) - Teck Resources Ltd said on Wednesday it has agreed to sell future silver production from a mine in Peru to Franco-Nevada Corp for $610 million in upfront funds, a cash boost for the debt-laden miner that sent its shares soaring.

The so-called "streaming" deal is on Teck's share of the by-product silver production from the large Antamina copper mine in Peru. Vancouver-based Teck owns a 22.5 percent stake in Antamina.

In streaming transactions, mining finance companies such as Franco-Nevada provide miners with funds upfront in exchange for a portion of the future production from a mine at a set, discounted price.

This type of alternative finance has been emerging as the new go-to funding for miners bowed by debt as weak share prices, courtesy of a four-year commodities' downturn, make raising equity finance expensive.

The deal is beneficial for Teck "as it adds cash immediately to Teck's balance sheet particularly after the recent credit rating downgrades on the company," Barclays analyst Farooq Hamed said in a note to clients.

In terms of the transaction, Toronto-based Franco-Nevada will also pay 5 percent of the spot silver price for each ounce of silver delivered under the stream.

Franco-Nevada said it expects 900,000 ounces to 1.1 million ounces of silver from the Antamina mine in the fourth quarter.

The transaction reduces Franco-Nevada's firepower to fund further deals in the short term, Barclays' Hamed said, coming two days after the company revised a $1 billion streaming deal with miner First Quantum Minerals.

Miner and trader Glencore , whose shares have been hammered by worries about its debt burden, is also working on a streaming transaction on its stake in the Antamina mine, sources said last month. (Reporting by Nicole Mordant; Additional reporting by Anannya Pramanick in Bengaluru; Editing by Shounak Dasgupta and Lisa Shumaker)